Square planar platinum complexes such as cis- (NH.sub.3).sub.2 Pt(II)Cl.sub.2 are known. Their widespread use as chemotherapeutic drugs, however, is limited by their rapid rate of excretion and the kidney damage which results from this effect. It has also been shown that the chemotherapeutic effects of these compounds are accompanied by such toxic side effects as bone marrow depletion and damage to the intestinal mucosa.
It is hypothesized that many of these side effects, particularly kidney damage, result from the fact that the platinum derivatives are small-molecule complexes that can be excreted rapidly through the semipermeable membranes of the kidney system.
It is an object of the invention to provide cis- platinum (II) complexes and salts which are effective anti-cancer agents but which do not exhibit toxic side effects such as kidney damage.